jw = Just wondering?
No hp gain from the Boss sidepipes as far as I know. 6-8hp isn't going to be noticeable and would be within the margin of error on a dyno, especially a supercharged car.
You're right. Boss sidepipes = nothing. The shape of the pipes causes a high pressure system anyway that restricts flow out the openings in the first place. Yes, exhaust still exists but doesn't affect real world flow.